Valve switchbox

ABSTRACT

A switchbox for monitoring the position of a manual quarter-turn valve has a housing mountable to the valve to be monitored/controlled. A handle-driven shaft extends through the housing, with one end of the shaft couplable to the valve stem such that movement of the shaft moves the valve stem. One or more shaft position sensor switches interact with a cam on the shaft to signal shaft position and/or provide control signals. A plate coupled to the shaft articulates within a recess on the surface of the switchbox to limit motion of the valve to an operable range, such as between full ON and full OFF. The switchbox has a pair of lock tabs with lock apertures. A lock aperture in the plate is alignable with the lock tab apertures to receive a pin or padlock for locking the valve in a selected position. A potentiometer can be utilized in place of a switch as a shaft position sensor. The switchbox may be used with an original or new handle and may feature detents to allow a range of valve settings.

CROSS-REFERENCED TO RELATED APPLICATION

This application is a divisional of, and claims the benefit of priorityto, U.S. patent application Ser. No. 13/019,097, filed on Feb. 1, 2011,the contents of which are incorporated herein by reference in theirentirety for all purposes.

FIELD OF THE INVENTION

The present disclosure generally relates to apparatus for monitoring andcontrolling valves and more particularly to switchboxes with limitswitches for controlling and monitoring manually operated, quarter-turnvalves.

BACKGROUND OF THE INVENTION

Valves, such as ball valves and butterfly valves are ubiquitous forcontrolling fluid flow through piping and conduits in many environments.For example, in the industrial environment, valves control the flow offluids and gasses through pipelines for material supply, venting,cooling/heating, hydraulic actuation and many other applications. Whilein the past, control valves were typically operated by hand, automatedvalve operation is becoming more common since it permits computerizedand remote operation/control, e.g., from a control room, eliminatingmanual operation and its attendant labor and risks. In many instances,it is important to keep a valve opened or closed, within a predeterminedrange of operation, or at a specific degree of openness. Theseconstrictions on valve position can be monitored and/or implemented bylimit switches, which sense on valve position and either send a signalrepresentative of position or enable/disable-open/close a circuit whichcan be used to control process equipment, e.g., a pump which pumps fluidthrough a pipeline controlled by the valve on which a limit switch isinstalled. It is known to utilize limit switches on electrically,pneumatically and hydraulically actuated valves to provide a mechanismfor controlling valve position (to keep the valve within a predeterminedrange of motion), as well as to provide signal data indicative of valveposition. While automated valves have become common, manual valvescontinue to be used, e.g., for backup purposes, such as for valves thatmay be actuated when the automatic valve or its supporting system (e.g.,electrical power) fails or is purposely shut down. Manual valves areused as override valves for maintenance purposes and in emergencies,e.g., to assure that a pipeline is shut off. Further, a manual valvemay, at times, be utilized for establishing a static degree of openness,e.g., for establishing a constant, reduced flow rate through a system.While limit switch use on manually-actuated valves is known, there is aneed for limit switches and switchboxes having improved features andfunctionality, e.g., pertaining to retro-fitability and compatibility toexisting valve assemblies, lockout capabilities, corrosion resistanceand capability to maintain a given valve setting.

SUMMARY OF THE INVENTION

The present disclosure relates to apparatus to aid in controlling avalve having a body, a passageway through the body and an articulablemember mounted to a valve stem and positioned within the passageway, theposition of the articulable member determining the degree of openness ofthe passageway. The apparatus has a housing removably attachable to thevalve body, a shaft extending through the housing, with one end of theshaft couplable to the valve stem such that movement of the shaft movesthe valve stem. A shaft position sensor interacts with a position sensoractuator coupled to the shaft, with the position sensor actuator capableof inducing the shaft position sensor to acquire a state having anassociated electrical property indicative of shaft position. Theapparatus has a motion limiter coupled to the shaft for limiting therange of motion of the shaft and rotating conjointly there with. A firstlock member is coupled to the shaft and rotates conjointly therewith. Asecond lock member is coupled to the body, the first and second lockmembers selectively cooperative to allow the shaft to be locked in afirst position. In accordance with an embodiment of the presentdisclosure, the motion limiter and the first lock member may bemonolithic.

In accordance with a method of the present disclosure for controlling amanually operated valve having a body, a passageway through the body, anarticulable member mounted to a valve stem and positioned within thepassageway, the position of the articulable member determining thedegree of openness of the passageway and an original handle attachableto the valve stem to facilitate turning the valve stem, the followingsteps may be conducted. Removing the original handle, then installing aswitchbox on the valve, the switchbox having a housing removablyattachable to the valve body, a shaft extending through the housing, oneend of the shaft couplable to the valve stem such that movement of theshaft moves the valve stem, a shaft position sensor, a position sensoractuator coupled to the shaft, the position sensor actuator capable ofinteracting with the shaft position sensor to induce the shaft positionsensor to acquire a state having an associated electrical propertyindicative of shaft position, a motion limiter coupled to the shaft forlimiting the range of motion of the shaft and rotating conjointly therewith, a first lock member coupled to the shaft and rotatable conjointlytherewith, a second lock member coupled to the body, the first andsecond lock members selectively cooperative to allow the shaft to belocked in a first position. Installing one of the original handle oranother handle. Selectively monitoring electrical signals from theposition sensor representative of a position of the shaft; andselectively locking the valve in a selected position.

Additional features, functions and benefits of the disclosed apparatus,systems and methods will be apparent from the description and claimswhich follow, particularly when read in conjunction with the appendedfigures.

BRIEF DESCRIPTION OF THE DRAWINGS

To assist those of ordinary skill in the art in making and using thedisclosed apparatus, reference is made to the appended figures, wherein:

FIG. 1 is perspective view of a switchbox mounted on a valve inaccordance with an embodiment of the present invention.

FIG. 2 is a top view of the assembly of FIG. 1.

FIG. 3 is a cross-sectional view of a handle pawl and detent of theassembly of FIGS. 1 and 2 taken along section line 3-3 and looking inthe direction of the arrows.

FIG. 4 is an enlarged perspective view of the switchbox of FIGS. 1 and 2separated from the valve, with the handle removed and seen from the top.

FIG. 5 is an enlarged perspective view of the switchbox of FIG. 4 seenfrom the bottom.

FIG. 6 is front view of the switchbox of FIG. 4 in elevation.

FIG. 7 is right side view of the switchbox of FIG. 4 in elevation.

FIG. 8 is rear view of the switchbox of FIG. 4 in elevation.

FIG. 9 is left side view of the switchbox of FIG. 4 in elevation.

FIG. 10 is top view of the switchbox of FIG. 4.

FIG. 11 is bottom view of the switchbox of FIG. 4.

FIG. 12 is a exploded view of the switchbox of FIG. 4.

FIG. 13 is an enlarged perspective view of the interior of the switchboxof FIG. 4 with the cover and lock plate removed.

FIG. 14 is a cross-sectional view of the switchbox of FIG. 4 taken alonglines 14-14 and looking in the direction of the arrows.

FIG. 15 is perspective view a switchbox in accordance with an embodimentof the present invention mounted on a ball valve.

FIG. 16 is a top perspective view of a switchbox with a valve mountingadapter in accordance with an embodiment of the present invention.

FIG. 17 is a bottom perspective view of the device shown in FIG. 16.

FIG. 18 is a bottom view of the device of FIG. 16.

FIG. 19 is an exploded view of a switchbox in accordance with anexemplary embodiment of the present invention and having a adaptersleeve on the input shaft.

FIG. 20 is a perspective view of the interior of a switchbox inaccordance with an exemplary embodiment of the present invention, withthe cover removed.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

FIGS. 1 and 2 show a valve switchbox 10 in accordance with an embodimentof the present invention attached to the mounting plate 12 of abutterfly valve 14. This attachment may be accomplished by a pluralityof screws or bolts extending up through the mounting plate 12 intothreaded apertures in the switchbox 10, drawing the switchbox 10 intoclose mechanical engagement with the mounting plate 12. Alternatively,the mounting plate 12 could utilize a plurality of threaded studs or theswitchbox 10 could have a plurality of apertures therein to allow boltsto secure the switchbox 10 to threaded apertures in the mounting plate12. The valve 14 has a body 16 in which a shaft-mounted disc 18articulates to open and close a throat 20 through which a fluid may pass(when open). In this disclosure, “fluid” would include liquids, gasesand flowable solid particulates, etc. A handle 22 on the switchbox 10 isused to control the position of the disc 18 in the valve throat 20.Typically, a valve, such as valve 14, would be provided with a handlethat would be attached directly to the shaft supporting the disc 18. Asshown in FIG. 1, the valve switchbox 10 of the present disclosure can bepositioned to intermediate between the handle 22 and the valve 14. Anoptional aspect of the present disclosure is that the handle of anexisting valve 14 can be utilized with the switchbox 10 in instanceswhen the switchbox 10 is retrofitted to the valve 14. In this manner,the handle will likely be properly sized for the given application,e.g., long enough to provide sufficient leverage to allow operation, aswell as properly marked and colored, e.g., with indicia and colorssymbolic of valve function, for identifying the composition of the fluidthat is controlled by the valve 14, as well as open and closedirections, warnings, etc. Alternatively, a new handle can be utilizedwith the switchbox 10, which has attributes more appropriate for thetask it must perform. As shown in FIGS. 1, 2 and 3, the handle 22 may beprovided with a position lock release 24, e.g., having a trigger leverthat releases a positioning tooth 40 from an associated detent 36 toallow the valve 14 to be selectively locked in position and unlocked toallow re-positioning.

The switchbox 10 features a lock plate 26 that turns in unison with thehandle 22 and is positionable in alignment with lock tabs 28 or 30 suchthat when the aperture 26 a of the lock plate 26 is aligned with eitheraperture 28 a or 30 a, a pin, padlock, cable or other lock may beinserted there through to hold valve 14 in a specific position. Thesefeatures may be utilized as safety features, e.g., to retain a valve 14in the closed position while maintenance is conducted down-line of thevalve 14 (to prevent someone from opening the valve inadvertently).Alternatively, the valve may need to be locked open to provide essentialsupply of material or cooling fluid down-line. The lock plate 26 mayalso have a configuration that allows it to function as a motionlimiter. More particularly, the lock plate 26 shown may be limited to arange of motion between stop surface 34 (valve closed position) and stopsurface 32 (valve open position). Alternatively, the switchbox 10 may beconfigured to allow full rotation of the valve 14 or embody differentlimits on the range of motion of the valve 14 by varying the position ofthe stop surfaces 32, 34, the shape and dimensions of the stop plate 26,or by utilizing moveable stop surfaces 32, 34 on adjustable (moveable)stops. As shown in FIGS. 2 and 3, detents 36 may be provided on theswitchbox 10 to enable the handle 22 (and disc 18) to be movablypositioned to a selected position (representing an associated degree ofopenness of the valve 14). The detents 36 permit the valve 14 to bepositioned at a selected intermediate position between the opened andclosed positions and to retain that selected position notwithstandingthe force of fluid flow through the valve (until purposely repositionedby an operator). A spring or other resilient member (not shown) may beused to bias the tooth 40 into engagement with a detent 36. The variouspositions of the valve, instructions for use and other information maybe expressed by indicia 38 a-d that may be embossed or otherwise placedon the switchbox 10.

FIGS. 4-11 show that the switchbox 10 has a cover 42 and a base 44,which may be attached by bolts or other fasteners 46 distributed aroundthe periphery of the switchbox 10. Alternatively, the cover 42 may beglued or fused to the base 44, which would prevent access to theinterior of the switchbox, which may or may not be preferred, dependingupon the application, e.g., considering the non-adjustability andreliability of internal components, cost and other factors. A shaft 48extends through the cover 42 for fitting to a handle or other turningapparatus, such as a motor driven member. The shaft 48 may be providedwith a threaded aperture 50 for receiving a bolt or screw to hold thehandle 22 on the shaft 48. Alternatively, the shaft 48 may retain thehandle 22 by means of an interference fit, a set screw or otherconventional means. The opposing mating surfaces 52, 54, respectively ofthe cover 42 and the base 44 have a generally complementary castellatedshape, which prevents relative shearing motion and allows the fasteners46 (disposed proximate the corners of the switchbox 10) to be recessedbelow the upper surface 56 of the cover 42 without substantiallythinning the cover thickness. Recessing the fasteners below the surfacepermits the lock plate 26 to pass there over, as well as facilitatinghandle operation (without hitting knuckles or the handle 22) onupstanding fasteners 46 and also resists contaminant infiltration at thefastener openings 42 b, 44 b in the cover 42 and base 44, respectively(see FIG. 12). The upper surface of the cover 42 features a recessedarea 58 defining the area through which the lock plate 26 can bearticulated and delimited by the stop surfaces 32 and 34. The lock plate26 shown is generally triangular in shape, but could be other shapes,depending upon the shape of the recessed area 58. When rotated to abutstop surface 34 (illustrated to be the closed position for the valve 14)the aperture 26 a aligns with aperture 28 a (see FIGS. 4 and 5) in locktab 28, allowing a lock (not shown) to be slipped through the alignedapertures 26 a, 28 a, preventing the lock plate 26, shaft 48, handle 22and valve 14 from being turned from the closed position. As shown inphantom view, the lock plate 26 can be rotated counter-clockwise to aposition abuting stop surface 32 to the open position and locked therevia lock tab 30. Detents 36 communicate with a relief groove 60 thatcommunicates with the recessed area 58 of the cover 42 and optionallymay extend across the recessed area (see FIG. 12). The relief groove 60permits materials, e.g., fluids, which spill or condense on the cover inthe area of the detents 36 to flow out of the detents 36, onto therecessed area 58 and off the cover 42. The recessed area 58 may alsoincorporate a groove or gutter (not shown) to channel fluids off thecover 42. In this manner, the likelihood of fluid intrusion intoswitchbox 10 or damage of the switchbox 10 by solvents is reduced andany fluids which could otherwise fill and obstruct the detents 36, e.g.,after drying and hardening, is drained before drying. As shown in FIG.4, the lock plate 26 may incorporate reliefs 26 b and 26 c toaccommodate portions of the handle 22 in a retrofit application. Thelock plate 26 has a shaft aperture 26 d which mates with the shaft 48 toassure conjoint rotation. As shown more clearly in FIG. 13, the shaft 48has a bead 48 d accommodated in a mating recess in the shaft aperture 26d which assures a specific shaft-to-lock plate assembly orientation.

FIG. 5 shows that the bottom surface 62 of the switchbox 10 may have aplurality of mounting apertures, 64, e.g., for accommodating studs orscrews (not shown). In the instance where the switchbox 10 is attachedto a valve mounting plate 12 via bolts, the apertures 64 may bethreaded. A plurality of apertures 64 may be provided to match a varietyof bolt/fastener patterns and permit the switchbox 10 to be mounted to avariety of valves (mounting plates or adapters). An output socket 66extending from or coupled to the shaft 48 has a central aperture 68adapted to matingly accommodate a valve shaft in order to transferrotational motion to the valve shaft. Alternatively, the centralaperture 68 can be fitted with an adapter bushing 70 (see FIG. 14) forintermediating between the shape of the central aperture 68 and theshape of a given existing valve shaft. An adapter bushing 74 (see FIG.19) may also be utilized to adapt a given shaft 48 to a given handle 22.

FIG. 7 shows that the base 44 may be provided with an opening 72 toaccommodate electrical wiring and may be adapted to receive andcooperate with electrical conduit to protect electrical wires enteringthe switchbox 10 and prevent intrusion of contaminants into theswitchbox 10. Alternatively, quick-disconnect electrical connectors,such as Hirschmann connectors, pin connectors or the like may be used toconnect external wiring to electrical components, e.g., switches 76, 78(see FIG. 12) inside switchbox 10.

FIG. 11 shows that the fastener 46 may be a bolt that interacts with anut captured in base 44.

FIG. 12 shows the interior contents of the switchbox 10, i.e., withinthe interior hollow 10 a thereof. The shaft 48 has an upper portion 48 aadapted to couple to a handle 22 and a lower portion 48 b, the outerexterior surface of which functions as a cam. A bottom portion 48 cextends through a bore 44 a in the base 44 to couple to a valve shaft(not shown) directly, or via an adapter 70. While a one-piece shaft 48is depicted, the cam shape of the lower portion 48 b could be executedas a separate element which could be glued, welded, keyed or otherwiseretained on shaft 48 so as to turn in unison with the shaft 48. In theinstance of a removable, separate cam element, a variety of cam shapescould be fitted to the shaft 48 in order to accommodate a variety ofdifferent switchbox applications. The lower portion 48 b turns relativeto switches 76, 78, which are mounted on corresponding mounting plates80, 82, respectively, which feature recesses 80 a, 82 a, respectivelyfor matingly receiving and holding the switches 76, 78 in a stableposition. The switches 76, 78 may be retained in the recesses 80 a, 82 aby screws, rivets, glue or any conventional means. The mounting plates80, 82 are retained by screws that thread into the base 44. Slottedholes 84 in the mounting plates 80, 82 permit adjustment along the rangelimited by the slotted holes 84, such that the switches can bepositioned to actuate at a particular angular position of the cam.During installation, the valve 14 can be placed in a selected position,then the position of the switches 76, 78 adjusted. Proper operation canbe verified based on switch 76, 78 output. Terminal blocks 86, 88 areretained in retainers 90 extending from the interior of the base 44 toretain wires (not shown) entering the switchbox 10 through opening 72.Alternatively, the terminal blocks 86, 88 could be retained in theswitchbox 10 by screws, rivets, glue or any other conventional means, orthe wiring could be connected directly to the switches 76, 78 withoutconnecting to terminal blocks 86, 88. Seals 92 a, 92 b and 92 c seal thecover 42 and the base 44 to the shaft 48 and the cover 42 to the base44, respectively, preventing intrusion of contaminants into theswitchbox 10.

FIGS. 13 and 14 show the switches 76, 78 mounted to the mounting plates80, 82, which are attached to the base 44. The terminal blocks 86, 88are retained by retainers 90. (No wires are shown running between theexterior and the terminal blocks 86, 88 or between the switches 76, 78and the terminal blocks 86, 88 for simplicity of illustration.) Theshaft 48 has a lock plate mounting area 48 e featuring a bead 48 d thatmates with a corresponding relief in the lock plate aperture 26 d toestablish a specific assembly orientation of the lock plate 26 relativeto the shaft 48 and the lower portion 48 b (cam). The switches 76, 78may be used to signal the position of the shaft 48 by the cam shape oflower portion 48 b, i.e., by being turned ON/OFF due to cam action onthe switches, moving a switch actuator lever or button. Alternatively,switch operation may be a signal to turn an associated device, e.g., apump, ON/OFF. For example, a pump which pushes fluid through the valve14 may be disabled by a switch 76 or 78 when the shaft 48 is turned to aposition representing a closed position of the valve 14, preventing thepump from exercising the fruitless function of attempting to urge afluid through a closed valve. Using the same example, the OPEN positionof the valve 14 may cause a switch 76, 78 to enable running of the pump.The switches 76, 78 may also be used to inform an operator or computercontroller that the valve has achieved a specific position,corresponding to a degree of openness. For example, a closed valve 14may cause a switch 76, 78 to signal to a controller that the valve is ina closed condition, such that the controller (human or automatic) willterminate pump operation. Further, if a signal is given to move thevalve to the open condition, a switch 76, 78 may inform a controllerthat the valve 14 has achieved the desired state of openness. Theswitchbox 10 can accommodate more or fewer switches, each switchpotentially performing indicating functions and/or enabling/disablingfunctions at selected positions of the valve 14. The switchbox 10 may beused for data collection (pertaining to valve position over time) andfor process tracking.

FIG. 15 shows the switchbox 10 used in conjunction with a ball valve 94with a T-handle 96, which, as shown, does not incorporate a detentengagement apparatus. Alternatively, the T-handle could incorporate amechanism to engage detents 36.

FIGS. 16-18 show the switchbox 10 coupled to a mounting plate adapter 98having a primary mounting plate 98 a which would be coupled to a valve,like valve 14 or 94, a secondary mounting plate 98 b which couples tothe switchbox 10, and an intermediate portion 98 c connecting theprimary and secondary mounting plates 98 a and 98 b. The coupling of themounting plate adapter 98 to the valve 14, 96 may be by screws, nuts andbolts, studs or bolts threadedly received in apertures 64, 98 d, clampsor other conventional means.

FIG. 19 shows a switchbox 10 which utilizes an adapter bushing 74 on theupper portion of the shaft 48 a to receive a mating handle, such ashandle 22 (see FIG. 1). The adapter bushings 70 (see FIG. 12) and 74,mounting plate adapter 98 (see FIG. 16) and the provision of a pluralityof mounting aperture 64 patterns, promote the universal use of theswitchbox 10 to a variety of valve applications with either the originalvalve handle or a replacement handle 22. In the instance that theoriginal handle incorporates lockout features that are incompatible withthe switchbox 10, the switchbox 10 provides any necessary lockoutfeature, i.e., via the interaction of a lock with the lock plate 26 andlock tabs 28, 30 (through alignment of the aperture 26 a, with aperture28 a or 30 a and insertion of the lock through the aligned apertures).It is understood that a manual valve may have lockout features whereasan automated valve may not, in that, a locked-out condition of amanually operated valve will be observable to the operator of the valveand no effort would be expended in futilely attempting to turn thevalve. In the instance of an automated valve, the automated valveactuator may not have a means to sense that the valve is locked and theactuator may futilely attempt turning resulting in damage to the valveor the actuator.

FIG. 20 shows a switchbox 110 wherein one of the switches is replacedwith a potentiometer 111. The potentiometer 111 can signal a variableresistance based upon rotational displacement, such that a potentiometergear 113 which is rotated by a shaft-mounted gear 115 can be utilized toascertain the rotational position/displacement of the shaft 148 (and anassociated valve (like valve 14 or 94) via electronic interpretation ofthe potentiometer output, such as by an analog-to-digital converter. Inthis manner, the position of the shaft and associated valve can bedetermined at any position and is not restricted to discrete positionsassociated with cam-induced switch signaling. The potentiometer 111 andpotentiometer gear 113 can be retrofitted to a shaft 148 having aconfiguration like that of shaft 48 shown in FIG. 12 and can optionallybe used in conjunction with one or more cam-driven switches 176. Becausea potentiometer output may be stored or interpreted as zero at any givenangular position of turn, there is no need to adjust the angularmounting position of the potentiometer 111 within the switchbox 110,e.g., by way of an adjustable mounting plate, such as 80, 82 (see FIG.12). A mounting plate, 80, 82 of an appropriate thickness could beutilized to establish the alignment of potentiometer gear 113 andshaft-mounted gear 115 by setting the height of the potentiometer 111.

The switchbox 10, 110 may be made from metal or plastic and suchmaterial may be selected to be corrosion-resistant and compatible with agiven piping system, e.g., plastic construction for a plastic pipingsystem. Plastics which may be used include PVC, CPVC and GFPP. Plasticcomposition is often lighter and may be preferred in applicationsrequiring lighter weight. These comments as to material of compositionapply to the cover 42, base 44, mounting plates 80, 82, as well as theshaft 48, 148. The shaft 48, 148 may also be made from 300 or 400 Seriesstainless steel or aluminum depending upon the application.

The switchbox 10 provides electronic indication/control based upon valveposition. These features can be conferred on a mechanically operatedvalve and the switchbox is retrofittable to a manual valve whichoriginally did not have such indication and control capability. Itshould be appreciated that a manually-operated valve 14 may be driven byautomated apparatus or vice versa, by subsequentconnection/disconnection from automated apparatus, such as a motor. Forexample, an automated valve may have the automatic rotating equipmentdisconnected and a handle installed either temporarily or permanently,in its place. In either case, the switchbox may be incorporated on thevalve intermediate either the manual handle or the automated turningapparatus, either permanently or temporarily.

What is claimed is:
 1. A method of controlling a manually operated valvehaving a body, a passageway through the body, an articulable membermounted to a valve stem and positioned within the passageway, theposition of the articulable member determining the degree of openness ofthe passageway and an original handle attachable to the valve stem tofacilitate turning the valve stem, comprises the steps of: (A) removingthe original handle; (B) installing a switchbox on the valve, theswitchbox having a housing removably attachable to the valve body, ashaft extending through the housing, one end of the shaft couplable tothe valve stem such that movement of the shaft moves the valve stem, ashaft position sensor, a position sensor actuator coupled to the shaft,the position sensor actuator capable of interacting with the shaftposition sensor to induce the shaft position sensor to acquire a statehaving an associated electrical property indicative of shaft position, amotion limiter coupled to the shaft for limiting the range of motion ofthe shaft and rotating conjointly therewith, a first lock member coupledto the shaft and rotatable conjointly therewith, a second lock membercoupled to the housing, the first and second lock members selectivelycooperative to allow the shaft to be locked in a first position, whereinthe housing has a base and a cover coupled to the base via a fastenermember, and wherein opposing mating surfaces of the cover and the basehave a complementary castellated shape that (i) allows the fastenermember to be recessed below an upper surface of the cover, and (ii)permits the motion limiter to pass over the fastener member duringrotation of the motion limiter; (C) installing one of the originalhandle or another handle; (D) selectively monitoring electrical signalsfrom the position sensor representative of a position of the shaft; and(E) selectively locking the valve in a first selected position.
 2. Themethod of claim 1, further including the step of calibrating theposition sensor by positioning the valve at a selected calibrationposition to produce an expected associated electrical output from theposition sensor, if the expected associated electrical output is notpresent, then adjusting the position of the position sensor until theelectrical output corresponds to the expected associated electricaloutput and then fixing the position of the position sensor.
 3. Themethod of claim 1, further including the step of locking the valve at asecond selected position.
 4. The method of claim 1, wherein the positionsensor is a potentiometer and further including the step of interpretingan electrical resistance of the potentiometer as an indication of anassociated angular position of the shaft.
 5. The method of claim 1,wherein the handle installed in said step (C) is the original handle. 6.The method of claim 1, wherein said step (B) of installing includesselecting a first set of mounting apertures in the switchbox forinserting fasteners therein for the valve, wherein the switchbox has asecond set of mounting apertures for inserting fasteners therein for asecond valve.